OvmfPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.c

   1 /** @file
   2   Provide constructor and GetTick for Base instance of ACPI Timer Library
   3
   4   Copyright (C) 2014, Gabriel L. Somlo <somlo@cmu.edu>
   5
   6   This program and the accompanying materials are licensed and made
   7   available under the terms and conditions of the BSD License which
   8   accompanies this distribution.   The full text of the license may
   9   be found at http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13 **/
  14
  15 #include <Library/DebugLib.h>
  16 #include <Library/IoLib.h>
  17 #include <Library/PciLib.h>
  18 #include <Library/PcdLib.h>
  19 #include <OvmfPlatforms.h>
  20
  21 //
  22 // Cached ACPI Timer IO Address
  23 //
  24 STATIC UINT32 mAcpiTimerIoAddr;
  25
  26 /**
  27   The constructor function caches the ACPI tick counter address, and,
  28   if necessary, enables ACPI IO space.
  29
  30   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
  31
  32 **/
  33 RETURN_STATUS
  34 EFIAPI
  35 AcpiTimerLibConstructor (
  36   VOID
  37   )
  38 {
  39   UINT16 HostBridgeDevId;
  40   UINTN Pmba;
  41   UINTN AcpiCtlReg;
  42   UINT8 AcpiEnBit;
  43
  44   //
  45   // Query Host Bridge DID to determine platform type
  46   //
  47   HostBridgeDevId = PciRead16 (OVMF_HOSTBRIDGE_DID);
  48   switch (HostBridgeDevId) {
  49     case INTEL_82441_DEVICE_ID:
  50       Pmba       = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMBA);
  51       AcpiCtlReg = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMREGMISC);
  52       AcpiEnBit  = PIIX4_PMREGMISC_PMIOSE;
  53       break;
  54     case INTEL_Q35_MCH_DEVICE_ID:
  55       Pmba       = POWER_MGMT_REGISTER_Q35 (ICH9_PMBASE);
  56       AcpiCtlReg = POWER_MGMT_REGISTER_Q35 (ICH9_ACPI_CNTL);
  57       AcpiEnBit  = ICH9_ACPI_CNTL_ACPI_EN;
  58       break;
  59     default:
  60       DEBUG ((EFI_D_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",
  61         __FUNCTION__, HostBridgeDevId));
  62       ASSERT (FALSE);
  63       return RETURN_UNSUPPORTED;
  64   }
  65
  66   mAcpiTimerIoAddr = (PciRead32 (Pmba) & ~PMBA_RTE) + ACPI_TIMER_OFFSET;
  67
  68   //
  69   // Check to see if the Power Management Base Address is already enabled
  70   //
  71   if ((PciRead8 (AcpiCtlReg) & AcpiEnBit) == 0) {
  72     //
  73     // If the Power Management Base Address is not programmed,
  74     // then program the Power Management Base Address from a PCD.
  75     //
  76     PciAndThenOr32 (Pmba, (UINT32) ~0xFFC0, PcdGet16 (PcdAcpiPmBaseAddress));
  77
  78     //
  79     // Enable PMBA I/O port decodes
  80     //
  81     PciOr8 (AcpiCtlReg, AcpiEnBit);
  82   }
  83
  84   return RETURN_SUCCESS;
  85 }
  86
  87 /**
  88   Internal function to read the current tick counter of ACPI.
  89
  90   Read the current ACPI tick counter using the counter address cached
  91   by this instance's constructor.
  92
  93   @return The tick counter read.
  94
  95 **/
  96 UINT32
  97 InternalAcpiGetTimerTick (
  98   VOID
  99   )
 100 {
 101   //
 102   //   Return the current ACPI timer value.
 103   //
 104   return IoRead32 (mAcpiTimerIoAddr);
 105 }